Chemistry alpha test


Hey guys, I am pretty confused with this problem. I calculated the pH and got pH zero, so isn’t the pOH supposed to be 14? The answer key says it is 13. Can someone pls kindly explain to me! Thanks ahead :ok_woman:t2::heart:

1 Like

Hi!

HCl ----- H⁺ + Cl⁻
n(HCl)=72/36=2
ratio 1:1 HCl:H⁺
So n(H⁺)=2

C=n/V=2/2=1
[H⁺]=1 so pH=1 i believe?

pOH=14-1=13

2 Likes

Hey Juliette! Thank you for replying❤️. I was thinking since pH = -log [H+] and conc of H+ is 1 molarity, and one is ten to the power zero, pH will be zero :(( , can we not take pH as zero in this problem?

Actually you’re right it should be 14
Ari’s trick: C=1,0 one zero after the comma so pH=0
also i found this video saying =0: What is the pH of 1.0 M HCl? - YouTube

2 Likes

Hey Juliette! Thank you very much for the help and also the video :two_hearts::two_hearts::two_hearts:

2 Likes